Datasheet

FLASH Memory (FLASH)
MC68HC908LJ12 — Rev. 2.1 Technical Data
Freescale Semiconductor FLASH Memory (FLASH) 65
4.6 FLASH Mass Erase Operation
Use the following procedure to erase the entire FLASH memory to read
as logic 1:
1. Set both the ERASE bit and the MASS bit in the FLASH control
register.
2. Write any data to any FLASH address within the FLASH memory
address range.
3. Wait for a time, t
nvs
(10µs).
4. Set the HVEN bit.
5. Wait for a time t
merase
(4ms).
6. Clear the ERASE bit.
7. Wait for a time, t
nvhl
(100µs).
8. Clear the HVEN bit.
9. After time, t
rcv
(1µs), the memory can be accessed again in read
mode.
NOTE: Programming and erasing of FLASH locations cannot be performed by
executing code from the FLASH memory; the code must be executed
from RAM. While these operations must be performed in the order as
shown, but other unrelated operations may occur between the steps.